1#ifndef __CURL_MULTI_H
2#define __CURL_MULTI_H
3/***************************************************************************
4 *                                  _   _ ____  _
5 *  Project                     ___| | | |  _ \| |
6 *                             / __| | | | |_) | |
7 *                            | (__| |_| |  _ <| |___
8 *                             \___|\___/|_| \_\_____|
9 *
10 * Copyright (C) 1998 - 2013, Daniel Stenberg, <daniel@haxx.se>, et al.
11 *
12 * This software is licensed as described in the file COPYING, which
13 * you should have received as part of this distribution. The terms
14 * are also available at http://curl.haxx.se/docs/copyright.html.
15 *
16 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
17 * copies of the Software, and permit persons to whom the Software is
18 * furnished to do so, under the terms of the COPYING file.
19 *
20 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
21 * KIND, either express or implied.
22 *
23 ***************************************************************************/
24/*
25  This is an "external" header file. Don't give away any internals here!
26
27  GOALS
28
29  o Enable a "pull" interface. The application that uses libcurl decides where
30    and when to ask libcurl to get/send data.
31
32  o Enable multiple simultaneous transfers in the same thread without making it
33    complicated for the application.
34
35  o Enable the application to select() on its own file descriptors and curl's
36    file descriptors simultaneous easily.
37
38*/
39
40/*
41 * This header file should not really need to include "curl.h" since curl.h
42 * itself includes this file and we expect user applications to do #include
43 * <curl/curl.h> without the need for especially including multi.h.
44 *
45 * For some reason we added this include here at one point, and rather than to
46 * break existing (wrongly written) libcurl applications, we leave it as-is
47 * but with this warning attached.
48 */
49#include "curl.h"
50
51#include <Availability.h>
52
53#ifdef  __cplusplus
54extern "C" {
55#endif
56
57typedef void CURLM;
58
59typedef enum {
60  CURLM_CALL_MULTI_PERFORM = -1, /* please call curl_multi_perform() or
61                                    curl_multi_socket*() soon */
62  CURLM_OK,
63  CURLM_BAD_HANDLE,      /* the passed-in handle is not a valid CURLM handle */
64  CURLM_BAD_EASY_HANDLE, /* an easy handle was not good/valid */
65  CURLM_OUT_OF_MEMORY,   /* if you ever get this, you're in deep sh*t */
66  CURLM_INTERNAL_ERROR,  /* this is a libcurl bug */
67  CURLM_BAD_SOCKET,      /* the passed in socket argument did not match */
68  CURLM_UNKNOWN_OPTION,  /* curl_multi_setopt() with unsupported option */
69  CURLM_ADDED_ALREADY,   /* an easy handle already added to a multi handle was
70                            attempted to get added - again */
71  CURLM_LAST
72} CURLMcode;
73
74/* just to make code nicer when using curl_multi_socket() you can now check
75   for CURLM_CALL_MULTI_SOCKET too in the same style it works for
76   curl_multi_perform() and CURLM_CALL_MULTI_PERFORM */
77#define CURLM_CALL_MULTI_SOCKET CURLM_CALL_MULTI_PERFORM
78
79typedef enum {
80  CURLMSG_NONE, /* first, not used */
81  CURLMSG_DONE, /* This easy handle has completed. 'result' contains
82                   the CURLcode of the transfer */
83  CURLMSG_LAST /* last, not used */
84} CURLMSG;
85
86struct CURLMsg {
87  CURLMSG msg;       /* what this message means */
88  CURL *easy_handle; /* the handle it concerns */
89  union {
90    void *whatever;    /* message-specific data */
91    CURLcode result;   /* return code for transfer */
92  } data;
93};
94typedef struct CURLMsg CURLMsg;
95
96/* Based on poll(2) structure and values.
97 * We don't use pollfd and POLL* constants explicitly
98 * to cover platforms without poll(). */
99#define CURL_WAIT_POLLIN    0x0001
100#define CURL_WAIT_POLLPRI   0x0002
101#define CURL_WAIT_POLLOUT   0x0004
102
103struct curl_waitfd {
104  curl_socket_t fd;
105  short events;
106  short revents; /* not supported yet */
107};
108
109/*
110 * Name:    curl_multi_init()
111 *
112 * Desc:    inititalize multi-style curl usage
113 *
114 * Returns: a new CURLM handle to use in all 'curl_multi' functions.
115 */
116CURL_EXTERN CURLM *curl_multi_init(void);
117
118/*
119 * Name:    curl_multi_add_handle()
120 *
121 * Desc:    add a standard curl handle to the multi stack
122 *
123 * Returns: CURLMcode type, general multi error code.
124 */
125CURL_EXTERN CURLMcode curl_multi_add_handle(CURLM *multi_handle,
126                                            CURL *curl_handle);
127
128 /*
129  * Name:    curl_multi_remove_handle()
130  *
131  * Desc:    removes a curl handle from the multi stack again
132  *
133  * Returns: CURLMcode type, general multi error code.
134  */
135CURL_EXTERN CURLMcode curl_multi_remove_handle(CURLM *multi_handle,
136                                               CURL *curl_handle);
137
138 /*
139  * Name:    curl_multi_fdset()
140  *
141  * Desc:    Ask curl for its fd_set sets. The app can use these to select() or
142  *          poll() on. We want curl_multi_perform() called as soon as one of
143  *          them are ready.
144  *
145  * Returns: CURLMcode type, general multi error code.
146  */
147CURL_EXTERN CURLMcode curl_multi_fdset(CURLM *multi_handle,
148                                       fd_set *read_fd_set,
149                                       fd_set *write_fd_set,
150                                       fd_set *exc_fd_set,
151                                       int *max_fd);
152
153/*
154 * Name:     curl_multi_wait()
155 *
156 * Desc:     Poll on all fds within a CURLM set as well as any
157 *           additional fds passed to the function.
158 *
159 * Returns:  CURLMcode type, general multi error code.
160 */
161__OSX_AVAILABLE_STARTING(__MAC_10_9, __IPHONE_7_0)
162CURL_EXTERN CURLMcode curl_multi_wait(CURLM *multi_handle,
163                                      struct curl_waitfd extra_fds[],
164                                      unsigned int extra_nfds,
165                                      int timeout_ms,
166                                      int *ret);
167
168 /*
169  * Name:    curl_multi_perform()
170  *
171  * Desc:    When the app thinks there's data available for curl it calls this
172  *          function to read/write whatever there is right now. This returns
173  *          as soon as the reads and writes are done. This function does not
174  *          require that there actually is data available for reading or that
175  *          data can be written, it can be called just in case. It returns
176  *          the number of handles that still transfer data in the second
177  *          argument's integer-pointer.
178  *
179  * Returns: CURLMcode type, general multi error code. *NOTE* that this only
180  *          returns errors etc regarding the whole multi stack. There might
181  *          still have occurred problems on invidual transfers even when this
182  *          returns OK.
183  */
184CURL_EXTERN CURLMcode curl_multi_perform(CURLM *multi_handle,
185                                         int *running_handles);
186
187 /*
188  * Name:    curl_multi_cleanup()
189  *
190  * Desc:    Cleans up and removes a whole multi stack. It does not free or
191  *          touch any individual easy handles in any way. We need to define
192  *          in what state those handles will be if this function is called
193  *          in the middle of a transfer.
194  *
195  * Returns: CURLMcode type, general multi error code.
196  */
197CURL_EXTERN CURLMcode curl_multi_cleanup(CURLM *multi_handle);
198
199/*
200 * Name:    curl_multi_info_read()
201 *
202 * Desc:    Ask the multi handle if there's any messages/informationals from
203 *          the individual transfers. Messages include informationals such as
204 *          error code from the transfer or just the fact that a transfer is
205 *          completed. More details on these should be written down as well.
206 *
207 *          Repeated calls to this function will return a new struct each
208 *          time, until a special "end of msgs" struct is returned as a signal
209 *          that there is no more to get at this point.
210 *
211 *          The data the returned pointer points to will not survive calling
212 *          curl_multi_cleanup().
213 *
214 *          The 'CURLMsg' struct is meant to be very simple and only contain
215 *          very basic informations. If more involved information is wanted,
216 *          we will provide the particular "transfer handle" in that struct
217 *          and that should/could/would be used in subsequent
218 *          curl_easy_getinfo() calls (or similar). The point being that we
219 *          must never expose complex structs to applications, as then we'll
220 *          undoubtably get backwards compatibility problems in the future.
221 *
222 * Returns: A pointer to a filled-in struct, or NULL if it failed or ran out
223 *          of structs. It also writes the number of messages left in the
224 *          queue (after this read) in the integer the second argument points
225 *          to.
226 */
227CURL_EXTERN CURLMsg *curl_multi_info_read(CURLM *multi_handle,
228                                          int *msgs_in_queue);
229
230/*
231 * Name:    curl_multi_strerror()
232 *
233 * Desc:    The curl_multi_strerror function may be used to turn a CURLMcode
234 *          value into the equivalent human readable error string.  This is
235 *          useful for printing meaningful error messages.
236 *
237 * Returns: A pointer to a zero-terminated error message.
238 */
239CURL_EXTERN const char *curl_multi_strerror(CURLMcode);
240
241/*
242 * Name:    curl_multi_socket() and
243 *          curl_multi_socket_all()
244 *
245 * Desc:    An alternative version of curl_multi_perform() that allows the
246 *          application to pass in one of the file descriptors that have been
247 *          detected to have "action" on them and let libcurl perform.
248 *          See man page for details.
249 */
250#define CURL_POLL_NONE   0
251#define CURL_POLL_IN     1
252#define CURL_POLL_OUT    2
253#define CURL_POLL_INOUT  3
254#define CURL_POLL_REMOVE 4
255
256#define CURL_SOCKET_TIMEOUT CURL_SOCKET_BAD
257
258#define CURL_CSELECT_IN   0x01
259#define CURL_CSELECT_OUT  0x02
260#define CURL_CSELECT_ERR  0x04
261
262typedef int (*curl_socket_callback)(CURL *easy,      /* easy handle */
263                                    curl_socket_t s, /* socket */
264                                    int what,        /* see above */
265                                    void *userp,     /* private callback
266                                                        pointer */
267                                    void *socketp);  /* private socket
268                                                        pointer */
269/*
270 * Name:    curl_multi_timer_callback
271 *
272 * Desc:    Called by libcurl whenever the library detects a change in the
273 *          maximum number of milliseconds the app is allowed to wait before
274 *          curl_multi_socket() or curl_multi_perform() must be called
275 *          (to allow libcurl's timed events to take place).
276 *
277 * Returns: The callback should return zero.
278 */
279typedef int (*curl_multi_timer_callback)(CURLM *multi,    /* multi handle */
280                                         long timeout_ms, /* see above */
281                                         void *userp);    /* private callback
282                                                             pointer */
283
284CURL_EXTERN CURLMcode curl_multi_socket(CURLM *multi_handle, curl_socket_t s,
285                                        int *running_handles);
286
287CURL_EXTERN CURLMcode curl_multi_socket_action(CURLM *multi_handle,
288                                               curl_socket_t s,
289                                               int ev_bitmask,
290                                               int *running_handles);
291
292CURL_EXTERN CURLMcode curl_multi_socket_all(CURLM *multi_handle,
293                                            int *running_handles);
294
295#ifndef CURL_ALLOW_OLD_MULTI_SOCKET
296/* This macro below was added in 7.16.3 to push users who recompile to use
297   the new curl_multi_socket_action() instead of the old curl_multi_socket()
298*/
299#define curl_multi_socket(x,y,z) curl_multi_socket_action(x,y,0,z)
300#endif
301
302/*
303 * Name:    curl_multi_timeout()
304 *
305 * Desc:    Returns the maximum number of milliseconds the app is allowed to
306 *          wait before curl_multi_socket() or curl_multi_perform() must be
307 *          called (to allow libcurl's timed events to take place).
308 *
309 * Returns: CURLM error code.
310 */
311CURL_EXTERN CURLMcode curl_multi_timeout(CURLM *multi_handle,
312                                         long *milliseconds);
313
314#undef CINIT /* re-using the same name as in curl.h */
315
316#ifdef CURL_ISOCPP
317#define CINIT(name,type,num) CURLMOPT_ ## name = CURLOPTTYPE_ ## type + num
318#else
319/* The macro "##" is ISO C, we assume pre-ISO C doesn't support it. */
320#define LONG          CURLOPTTYPE_LONG
321#define OBJECTPOINT   CURLOPTTYPE_OBJECTPOINT
322#define FUNCTIONPOINT CURLOPTTYPE_FUNCTIONPOINT
323#define OFF_T         CURLOPTTYPE_OFF_T
324#define CINIT(name,type,number) CURLMOPT_/**/name = type + number
325#endif
326
327typedef enum {
328  /* This is the socket callback function pointer */
329  CINIT(SOCKETFUNCTION, FUNCTIONPOINT, 1),
330
331  /* This is the argument passed to the socket callback */
332  CINIT(SOCKETDATA, OBJECTPOINT, 2),
333
334    /* set to 1 to enable pipelining for this multi handle */
335  CINIT(PIPELINING, LONG, 3),
336
337   /* This is the timer callback function pointer */
338  CINIT(TIMERFUNCTION, FUNCTIONPOINT, 4),
339
340  /* This is the argument passed to the timer callback */
341  CINIT(TIMERDATA, OBJECTPOINT, 5),
342
343  /* maximum number of entries in the connection cache */
344  CINIT(MAXCONNECTS, LONG, 6),
345
346  /* maximum number of (pipelining) connections to one host */
347  CINIT(MAX_HOST_CONNECTIONS, LONG, 7),
348
349  /* maximum number of requests in a pipeline */
350  CINIT(MAX_PIPELINE_LENGTH, LONG, 8),
351
352  /* a connection with a content-length longer than this
353     will not be considered for pipelining */
354  CINIT(CONTENT_LENGTH_PENALTY_SIZE, OFF_T, 9),
355
356  /* a connection with a chunk length longer than this
357     will not be considered for pipelining */
358  CINIT(CHUNK_LENGTH_PENALTY_SIZE, OFF_T, 10),
359
360  /* a list of site names(+port) that are blacklisted from
361     pipelining */
362  CINIT(PIPELINING_SITE_BL, OBJECTPOINT, 11),
363
364  /* a list of server types that are blacklisted from
365     pipelining */
366  CINIT(PIPELINING_SERVER_BL, OBJECTPOINT, 12),
367
368  /* maximum number of open connections in total */
369  CINIT(MAX_TOTAL_CONNECTIONS, LONG, 13),
370
371  CURLMOPT_LASTENTRY /* the last unused */
372} CURLMoption;
373
374
375/*
376 * Name:    curl_multi_setopt()
377 *
378 * Desc:    Sets options for the multi handle.
379 *
380 * Returns: CURLM error code.
381 */
382CURL_EXTERN CURLMcode curl_multi_setopt(CURLM *multi_handle,
383                                        CURLMoption option, ...);
384
385
386/*
387 * Name:    curl_multi_assign()
388 *
389 * Desc:    This function sets an association in the multi handle between the
390 *          given socket and a private pointer of the application. This is
391 *          (only) useful for curl_multi_socket uses.
392 *
393 * Returns: CURLM error code.
394 */
395CURL_EXTERN CURLMcode curl_multi_assign(CURLM *multi_handle,
396                                        curl_socket_t sockfd, void *sockp);
397
398#ifdef __cplusplus
399} /* end of extern "C" */
400#endif
401
402#endif
403